I always share the gratuity with my staff. They work their bums off for me and I feel they need to be rewarded for that. We always request the final check the morning of the event, before we finish cooking and serve. The client won't necessarily know how things will go at this point. For this particular couple they were very nice to work with, they called us at the last minute because their original caterer flaked on them. So, we bent over backwards to make it all work out for them with as little fuss and stress as possible. I don't like the idea of adding the gratuity on the bill, but my staff really deserved it for this one since they had to run up and down the stairs so many times.